Mechanism for driving and correcting a data disc in a day-date timepiece

ABSTRACT

In a day-date timepiece, a date disc is rotated step by step once every 24 hours by a correspondingly rotated day disc. The motion of the day disc is transmitted to the date disc through a disconnectable drive mechanism whereby the date disc can be corrected without disturbing the setting of the day disc or the time indication. The mechanism comprises a wheel solid with a pinion meshing with teeth on the outer periphery of the day disc. The wheel is rotated half a revolution at each step of the day disc. It is formed with two diametrically opposite slots down into which extend two studs of a transverse lever. A pair of springs hold the lever in a diametral position with the studs at the trailing end of the slots. Near the center of the lever are provided a pair of pins which engage in slots between teeth formed along the inner periphery of the day disc. At each half revolution of the lever-carrying wheel in an anticlockwise direction, the pins cause the date disc to advance one step. To correct the date, the date disc is moved in an anticlockwise direction by another mechanism not shown actuated from the winding stem. In so doing, the pins are forced out of the slots in the date disc to jump the teeth of the latter against the action of the springs with the lever being caused to pivot about one of its studs.

United States Patent 1 Vtiilleumier June 12, 1973 i541 MECHANISM FOR DRIVING AND I CORRECTING A DATA DISC IN A DAY- DATE TIMEPIECE [75] Inventor: Cyril Vuilleumier, Bienne,

Switzerland [73] Assignee: Omega, Louis Brandt & Frere S.A.,

Bienne, Switzerland [22] Filed: July 10, 1972 [21] Appl. No.: 270,302

52 us. Cl. 58/5, 58/58 Primary Examiner-George H. Miller, Jr. Att0rneyA. W. Molinare et al.

AIt0rneyA. W. Molinare, George B. Newitt, D. D. Allegretti et a1.

[57] ABSTRACT In a day-date timepiece, a date disc is rotated step by step once every 24 hours by a correspondingly rotated day disc. The motion of the day disc is transmitted to the date disc through a disconnectable drive mechanism whereby the date disc can be corrected without disturbing the setting of the day disc or the time indication. The mechanism comprises a wheel solid with a pinion meshing with teeth on the outer periphery of the day disc. The wheel is rotated half a revolution at each step of the day disc. It is formed with two diametrically opposite slots down into which extend two studs of a transverse lever. A pair of springs hold the lever in a diametral position with the studs at the trailing end of the slots. Near the center of the lever are provided a pair of pins which engage in slots between teeth formed along the inner periphery of the day disc. At each half revolution of the lever-carrying wheel in an anticlockwise direction, the pins cause the date disc to advance one step. To correct the date, the date disc is moved in an anticlockwise direction by another mechanism not shown actuated from the winding stem. In so doing, the pins are forced out of the slots in the date disc to jump the teeth of the latter against the action of the springs with the lever being caused to pivot about one of its studs.

8 Claims, 1 Drawing Figure MECHANISM FOR DRIVING AND CORRECTING A DATA DISC IN A DAY-DATE TIMEPIECE This invention relates to day-data timepieces.

Depending on the month, the date indicated by a calendar timepiece must be corrected, for example to jump the 3 1st day of a month. An object of the invention is to provide a mechanism which enables such a correction to be made without disturbing the remainder of the timepiece movement.

According to the invention there is provided a mechanism for driving a toothed date disc in a calendar timepiece, which comprises a step-by-step rotary part arranged to be moved one step once every 24 hours by the timepiece movement, a driving member in positive driven association with the rotary part and normally in meshing engagement with the toothing of said disc and causing said disc to be advanced by one date number at each step of the rotary part, said driving member being mounted on the rotary part for relative movement thereon between an operative, driving, position and an inoperative position, and elastic means secured to the rotary part and tending to maintain the driving member in said operative position, said rotary part and the teeth of said toothing being so shaped and disposed that the driving member is forced out of the toothing to said inoperative position against the action of the elastic means when the disc is advanced independently of the rotary part and of the driving member and remains in engagement with the toothing when the disc is driven by the rotary part and the driving member.

The single FIGURE of the accompanying schematic drawing, given by way of example, is a partial plan view of a calendar watch movement including'one form of embodiment of the driving mechanism according to the invention.

The movement shown in the drawing, insofar as it is illustrated, comprises an hour wheel which performs one complete revolution in the course every 12 hours. The wheel 10 is at the center of the movement and rotates about the axis of a fixed pinion 12 having l8 teeth. The wheel 10 carries a planet pinion 14 having 12 teeth which meshes with the fixed pinion 12 and which rotates about its own axis. The planet pinion 14 has a finger 16 arranged to cooperate successively with the 14 teeth 18 of the internal toothing of a day disc 20 (twice 7 days). The rotary parts 10, 14 and 20 rotate in the direction of arrows F1, F2 and F3, respectively. After one complete revolution of the wheel 10 from the illustrated position, the finger 16 is turned inwards and thus moves past the nearest tooth 18 without touching it. It is only after a second revolution of the wheel 10 that the finger 16 returns to the illustrated position to advance the day disc 20 one step.

The day disc 20 also has outer toothing 22 numbering l40 teeth. The toothing 22 meshes with a pinion 24 having 20 teeth which is solid (i.e. integral or secured) with a wheel 26 for driving a date disc 27. Thus, at each step of the day disc 20, the wheel 26 is rotated half a revolution. The wheel 26 has two peripheral notches 28 and 30 cooperating with a jumper 32 serving to hold the wheel 26 stationary between each rotational movement thereof.

Near its edge, the wheel 26 is formed with two curved slots 34 and 36 which occupy diametrically opposite positions. Into these slots extend two studs 38 and 40 which are solid with a lever 42 and which are turned downwards. The lever 42 is normally held on the wheel 26 in a diametral position, as shown in the drawing, by the free ends of two spring blades 44 and 46 whose opposite ends are anchored at 48 and 50 to the wheel 26. In this diametral position of the lever 42 the studs 38 and 40 find themselves at the trailing ends of the slots 34 and 36, considered in the rotational direction of the wheel 26, indicated by the arrow F4.

Near its center, the lever 42 has two upwardly turned pins 52 and 54 which engage in radial slots 56 separating thirty-one teeth 58 formed along the inner edge of the date disc 27. The distance between the pins 52 and 54 corresponds to the width of a tooth 58 near its tip. Each time the wheel 26 rotates through half a revolution, it drives therewith, in a positive manner, the lever 42 via the studs 38 and 40, thereby causing the pins 52 and 54 successively to advance the date disc 27 in the direction of the arrow F5, there always being at least one pin in engagement with the date disc 27.

When it is desired to correct the date, the date disc 27 is moved forward in the direction of the arrow F 5, e.g. to jump that one of the teeth 58 which corresponds to the 31st day of a month, by means of a mechanism, not shown, actuated from the winding stern of the watch, such correction taking place when the wheel 26 is stationary. During this displacement of the date disc 27, its teeth 58 force the pins 52 and 54 out of their slots 56 by causing the lever 42 to pivot, in the illustrated position, about the stud 38 and against the action of the spring 44 over a distance corresponding substantially to the length of the slot 36. In the other position of the wheel 26, i.e., the one in which the jumper engages the notch 28, the lever 42 pivots about the stud 40 against the action of the spring 46 and over a distance corresponding substantially to the length of the slot 34, the length of the slot 34 or 36 being sufficient to enable the pins 52 and 54 to clear the tips of the teeth 58.

Also, to enable such displacement of the pins 52 and 54 from their operative, driving, position (that shown) to an inoperative position under the action of an independent anticlockwise movement of the date disc 27, the teeth 58 are suitably shaped for the pins 52 and 54 to be forced out of the slots 56. Further, to enable the lever 42 to pivot about the stud 38 or 40, the center of curvature of the curved slots 34 and 36 is located near the trailing or upstream end of the other curved slot.

The disconnectable driving mechanism formed here by the wheel 26 with its pinion 24 and by the lever 42 with its pins 52 and 54 thus enables a positional correction of the date disc 27 not to be transmitted to the day disc 20 or to the hour wheel 10 since the jumper 32 will prevent any movement of the wheel 26, and hence of the day disc 20, during pivotal motion of the lever 42.

Various modifications may be made to the illustrated form of embodiment. For instance, the angular position of the lever 42 and of the curved slots 34 and 36 on the wheel 26 may be different, whilst retaining the illustrated position for the pins 52 and 54.

I claim:

1. In a day-date timepiece having a toothed date disc, a mechanism for driving said disc which comprises a step-by-step rotary part arranged to be moved one step once every 24 hours by the timepiece movement, a driving member in positive driven association with the rotary part and normally in meshing engagement with the toothing of said disc and causing said disc to be advanced by one date number at every step of the rotary part, said driving member being mounted on the rotary part for relative movement thereon between an operative, driving, position and an inoperative position, and elastic means secured to the rotary part and tending to maintain the driving member in said operative position, said rotary part and the teeth of said toothing being so shaped and disposed that the driving member is forced out of the toothing to said inoperative position against the action of the elastic means when the disc is advanced independently of the rotary part and of the driving member and remains in engagement with the toothing when the disc is driven by the rotary part and the driving member.

2. A mechanism according to claim 1, wherein said rotary part is rotated step by step by a continuously rotating wheel, revolving about the axis of a fixed pinion, via a driving element solid with a planet pinion carried by said continuously rotating wheel and meshing with said fixed pinion.

3. A mechanism according to claim ll, wherein said rotary part is rotated half a revolution once every 24 hours by a second rotary part and said driving member includes two pins arranged, in the operative position of the member, on opposite sides of the rotationalaxis of the first rotary part and cooperating, when said first rotary part is stationary, with the opposite flanks of a date disc tooth, said pins in turn causing the date disc to advance one step at each half revolution of the first rotary part.

4. A mechanism according to claim 3, wherein the pins are solid with a carrier element which is centered, in the operative position of the member, on the rotational axis of said first rotary part and which is normally held in this centered position by said elastic means, said carrier element having, on opposite sides of its center, pins in engagement with curved slots formed in said first rotary part on opposite sides of rotational axis of the latter, said pins abutting, in the operative position of the member, against the trailing end of their associated slot.

5. A mechanism according to claim 3, wherein said first rotary part comprises a wheel having two notches in diametrically opposite positions, said notches in turn cooperating with a jumper at the end of each half revolution of said first rotary part to lock said first rotary part, said second rotary part and, in the operative position of said member, the date disc between each of their steps.

6. A mechanism according to claim 3, wherein said second rotary part is a day disc.

7. A mechanism according to claim 3, wherein said. rotary part is rotated step by step by a continuously rotating wheel, revolving about the axis of a fixed pinion, via a driving element solid with a planet pinion carried by said continuously rotating wheel and meshing with said fixed pinion.

8. A mechanism according to claim 7, wherein said continuously rotating wheel is the hour wheel and said driving element successively cooperates at each second revolution of the hour wheel, with one of the teeth of a first toothing on said second rotary part, said second rotary part having a second toothing meshing with a toothing on said first rotary part. 

1. In a day-date timepiece having a toothed date disc, a mechanism for driving said disc which comprises a step-by-step rotary part arranged to be moved one step once every 24 hours by the timepiece movement, a driving member in positive driven association with the rotary part and normally in meshing engagement with the toothing of said disc and causing said disc to be advanced by one date number at every step of the rotary part, said driving member being mounted on the rotary part for relative movement thereon between an operative, driving, position and an inoperative position, and elastic means secured to the rotary part and tending to maintain the driving member in said operative position, said rotary part and the teeth of said toothing being so shaped and disposed that the driving member is forced out of the toothing to said inoperative position against the action of the elastic means when the disc is advanced independently of the rotary part and of the driving member and remains in engagement with the toothing when the disc is driven by the rotary part and the driving member.
 2. A mechanism according to claim 1, wherein said rotary part is rotated step by step by a continuously rotating wheel, revolving about the axis of a fixed pinion, via a driving element solid with a planet pinion carried by said continuously rotating wheel and meshing with said fixed pinion.
 3. A mechanism according to claim 1, wherein said rotary part is rotated half a revolution once every 24 hours by a second rotary part and said driving member includes two pins arranged, in the operative position of the member, on opposite sides of the rotational axis of the first rotary part and cooperating, when said first rotary part is stationary, with the opposite flanks of a date disc tooth, said pins in turn causing the date disc to advance one step at each half revolution of the first rotary part.
 4. A mechanism according to claim 3, wherein the pins are solid with a carrier element which is centered, in the operative position of the member, on the rotational axis of said first rotary part and which is normally held in this centered position by said elastic means, said carrier element having, on opposite sides of its center, pins in engagement with curved slots formed in said first rotary part on opposite sides of rotational axis of the latter, said pins abutting, in the operative position of the member, against the trailing end of their associated slot.
 5. A mechanism according to claim 3, wherein said first rotary part comprises a wheel having two notches in diametrically opposite positions, said notches in turn cooperating with a jumper at the end of each half revolution of said first rotary part to lock said first rotary part, said second rotary part and, in the operative position of said member, the date disc between each of their steps.
 6. A mechanism according to claim 3, wherein said second rotary part is a day disc.
 7. A mechanism according to claim 3, wherein said rotary part is rotated step by step by a continuously rotating wheel, revolving about the axis of a fixed pinion, via a driving element solid with a planet pinion carried by said continuously rotating wheel and meshing with said fixed pinion.
 8. A mechanism according to claim 7, wherein said continuously rotating wheel is the hour wheel and said driving element successively cooperates at each second revolution of the hour wheel, with one of the teeth of a first toothing on said second rotary part, said second rotary part having a second toothing meshing with a toothing on said first rotary part. 